Abstract: With the development of large scale switching network, the study is transferred from network layer to data link layer. The link layer topology discovery can discover the physical topology internal a LAN, which the network layer topology discovery can not discover. A link layer topology discovery algorithm based on spanning tree algorithm is proposed. The algorithm gets the STP information from the bridge MIBs with the tool of SNMP. It can calculate the link layer topology on the basis of the information. The algorithm is simple and with high performance in application.

Key words: STP, Topology discovery, Bridge MIB, SNMP

摘要： 随着大规模交换网络的发展，网络拓扑发现的研究由网络层拓展到数据链路层。链路层的拓扑发现能够发现网络层拓扑发现无法发现的局域网内部的详细的物理连接情况。该文提出了一种基于生成树算法的链路层网络拓扑发现算法，利用SNMP获得网桥MIB中的生成树信息，通过分析这些信息计算出链路层的网络拓扑，该算法相比其它算法更简单、高效，有应用价值。

关键词: 生成树协议, 拓扑发现, 网桥管理信息数据库, 简单网络管理协议